Investigation on materials removal rate and surface roughness of temperature resisted Waspaloy during electric spark machining utilizing gray relational analysis

Abstract

Waspaloy, a nickel-based super alloy, has much potential in gas turbine component production. Machining this type of material using the traditional manufacturing method is very hard. Hence, electrical discharge machining (EDM) was selected for the investigation of the machining characteristics of Waspaloy by choosing the control parameters, namely, current, voltage, pulse on time, pulse off time, and spark gap. Gray relational analysis is carried out using 18 experiments according to an orthogonal array (L18) to determine the gray relation grade for this machining process with multiple machining characteristics such as material removal rate (MR), tool wear rate (TW), and surface roughness (SR). The significant objective of the multi objective optimization to attain high MR, low TW, and low SR is found out. From gray relation optimization, the optimum machining conditions for EDM, namely, current: 26 A, voltage: 200 V, pulse on time: 120 μs, pulse on time: 10 μs, and spark gap: 0.15 m, have been identified. The foremost parameter affecting the responses was found to be peak current.